Bump coverlet.msbuild from 3.1.1 to 3.1.2 (#134)

Author: dependabot[bot]

test/Microsoft.VisualStudio.Validation.Tests/Microsoft.VisualStudio.Validation.Tests.csproj

@@ -7,7 +7,7 @@
     <PackageReference Include="xunit" Version="2.4.1" />
     <PackageReference Include="xunit.runner.visualstudio" Version="2.4.3" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.1.0" />
-    <PackageReference Include="coverlet.msbuild" Version="3.1.1" />
+    <PackageReference Include="coverlet.msbuild" Version="3.1.2" />
   </ItemGroup>
   <ItemGroup>
     <ProjectReference Include="..\..\src\Microsoft.VisualStudio.Validation\Microsoft.VisualStudio.Validation.csproj" />